Firearm with chamber member remov-



Feb. 28, 1956 R. E. CLARKSON ET AL FIREARM WITH CHAMBER MEMBER REMOVABLY CONNECTED ,TO RECEIVER FIG.I

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Mtg K ATTORN E United States Patent 3 FIREARM WITH CHAIVIBER MEMBER REMOV- ABLY CONNECTED TO RECEIVER Ralph E. Clarkson, Hamden, and Tuines W. van Wilgen,

Branford, Conm, assignors to Olin Mathieson Chemical Corporation, .a corporation of Virginia Application December 18, 1951, Serial No. 262,282 3 Claims. (CI. 42-75) This invention relates to firearms and has for its object the provision of an improved barrel therefor and means in combination therewith for connecting the barrel to the receiver of the gun. More particularly, the invention provides a. chamber member which has means for detachable connection to the receiver, and a light-metal barrel connected to the chamber member.

The barrel is preferably more or less permanently connected to the chamber member, as by full threads, and the chamber member is removably connected to the receiver, preferably for quick take-down, as by half threads. For take-down purposes the chamber member remains with the barrel. The chamber member is in effect a subbarrel of suflicient strength to be capable of containing the pressure generated by a fired cartridge. The chamber member withstands the force of the explosion, thus permitting the use of relatively lightweight barrels, preferably barrels formed of light-metals, such as magnesium, aluminum, and titanium and their base alloys. The invention, accordingly, comprises a lightweight barrel which need not have the usual high strength properties of conventional steel barrels, and a chamber member which is an interior lining means for withstanding the force of the explosion, the said chamber member also effecting the immediate or direct connection with the receiver.

In a preferred embodiment of the invention, the chamber member has a collar or annular flange against which a flat rearward face of the barrel makes abutting contact. The rear face of this collar or annular flange may also make an abutting contact with the receiver for the purpost of adjusting the chamber member and barrel to their precise location. The chamber member is longer than the shell to be fired and preferably comprises an extending relatively thin walled end section or neck which effects a fairly snug normal contact with the inside of the barrel and, when the gun is fired, expands within its elastic limit into sealing contact with the inside of the barrel.

These and other objects of the invention will be better understood after considering the following discussion taken in conjunction with the accompanying drawings, in which:

Fig. 1 is an exploded side elevation of part of a receiver, a chamber member and a section of barrel in one embodiment of the invention,

Fig. 2 is a side elevation, partly in section, of the three elements of Fig. l in joined relationship, and

Fig. 3 is a longitudinal sectional view of a shotgun barrel of the invention.

The embodiment of the invention illustrated in the drawings comprises a receiver 1 for any type of firearm whether it be single shot, repeater or semi-automatic, and a chamber member 2 having full threads 3 for the more or less permanent connection to the barrel 4. The barrel has a flat end shoulder 5 which makes abutting contact with the annular flange or collar 6 of the chamber member and the collar 6 makes abutting contact with the flat end 7 of the receiver so that the barrel and its chamber member may be adjusted and secured in precise location 2,736,118 Patented Feb. 28, 1956 on the receiver. The chamber member has half-thread sections 8 and 9 which engage complementary halfthread sections in the receiver and the barrel and chamber member may accordingly be removed as. a unit. for quick take-down purposes. Other means for removably connecting the chamber member to the receiver may be used.

Since the invention is applicable to any type of firearm such as single shot, repeating or semi-automatic, it will be understood that. various types of receivers may be used.

In the embodiment illustrated, the chamber member is constructed of any suitable high strength metal such as the alloy steels, plain nickel steel, nickel-vanadium steels, or stainless steel, or beryllium-copper alloy, and has the capacity to withstand, without rupturing, the gas pressure developed by the type and size of the cartridge to be used. The specific firearm construction used to particularly demonstrate the invention herein is. a shotgun. The interior of the chamber member is formed to standard dimensions in the usual manner to receive a standard shot shell. The wall thickness, the outside diameter and the length of the chamber in the member will vary with the gauge or size and length of shot shell to be used. Extending forwardly of the shell receiving portion of the chamber member is a neck portion 10 of reduced outside diameter and wall thickness for purposes hereinafter described.

It will be apparent from the foregoing description that, while the main portion of the chamber member has sufiicient strength to contain the pressure of explosion, the neck portion 10 of the forward part formed with thin side walls will expand in proportion to its thinness within its elastic limits and return to its original position. This expansion of the neck portion tends to seal the joint between the chamber member and barrel and thus prevent gas leakage and dirt deposit between the two members. Depending upon the characteristics of the metal, this reduced section can be thicker or thinner and it may be gradually tapered towards the end, the proportions being such that a seal is made between the neck and barrel without injurious expansion of the light-metal barrel.

The barrel may be constructed of any suitable light material such as a high tensile strength magnesium alloy, aluminum alloys, or titanium and its alloys. We may use a barrel as in Fig. 3 formed in part of a high strength aluminum alloy 12 having a cladding 13 of relatively pure aluminum on the inside, and a similar cladding 14 on the outside to minimize shattering. The cladding may be used only on the inside or on the outside. 'A barrel formed of an aluminum alloy with the foregoing chamber member construction has been successfully fired many time. The areas surrounding the chamber can be more or less cylindrical having an outside configuration approximating the usual steel barrel. The barrel bore surrounding the thick walled section of the chamber may have a reasonable clearance, while the bore surrounding the thin walled neck portion 10 is in snug but freely slidable contact whereby on expansion of the neck portion a sealing contact is made with the barrel.

The aluminum barrels may be anodized both inside and outside, the inside anodic coating giving a harder surface, while the outside anodic coating is receptive to dyes and can be colored to simulate a blued steel barrel.

We claim:

1. The improvement in firearms which comprises a chamber member of sufiicient thickness and strength to contain the explosive force of a shell, an aluminum barrel mounted over the major portion of the chamber member in fixed connection with respect thereto, and means for removably connecting the chamber member to a receiver in an immovable operative position, whereby the chamber member and barrel are removable as a unit.

2. The improvement in firearms which comprises a chamber member formed of a high tensile strength metal having a wall section surrounding the chamber capable of containing the force of an explosion therein and a neck section which is appreciably thinner than the-wall section surrounding the chamberextending therefrom, a barrel concentrically disposed over the chamber member and neck section and attached to the chamber member and making a snug contact with the neck section, said neck section being sufficiently thin and normally lying sufficiently close to the barrel that upon an explosion in said chamber it will expand within its elastic limits into sealing contact with the barrel, and means for effecting a removable but operative fixed connection of the chamber member to a receiver, whereby the chamber member and barrel are removable as a unit.

3. The improvement in firearms which comprises a receiver, a chamber member of sufiicient thickness and strength to contain the explosive force of a shell, said chamber member having connecting means juxtaposed on its exterior surface and separated by a stop means, an aluminum barrel telescoped over a major portion of said chamber member and maintained in fixed connection with respect thereto by the connecting means at one side of said stop means, the portion of the chamber member at the other side of the stop means being inserted into the receiver and detachably attached thereto by the connecting means at said other side of the stop means, whereby the chamber member and barrel are removable as a unit from the receiver, the stop means being in abutting engagement with both the receiver and the barrel.

References Cited in the file of this patent UNITED STATES PATENTS 1,234,783 Mauser July 31, 1917 1,355,422 Pedersen Oct. 12, 1920 1,628,798 Nelson May 17, 1927 1,864,374 Romberg et al June 21, 1932 2,440,634 Henney Apr. 27, 1948 2,476,232 Williams July 12, 1949 FOREIGN PATENTS 831,030 France May 30, 1938 OTHER REFERENCES Metals Handbook, 1948 edition, published by American Society for Metals, Cleveland, Ohio, pages 793-4. 

